Trouble packetizing h264 stream in FU-A mode over RTP UDP

Question

I am having some trouble packetizing an h.264 stream using SIP and RTP over UDP. I am using the FU-A packetization mode for a video avc track in an mp4. I spent time to get the fragmentation correct, with the duration timestamp on the RTP packet, as well as setting the marker bit at the last packet on the fragmented unit. Can someone take a look at the packets I posted below link which streams the mp4 indicated below. You will want to check the first h264 RTP stream in the wireshark pcap with ssrc 0x1653 which is the stream that I am trying to packetize. The video phone which is receiving the stream does not display the stream and I am trying to troubleshoot why. Thanks for any analysis. Paul

http://antinori.us/h264.packets.pcap

http://antinori.us/beck-videoplayback.mp4

Answer 1

First of all I don't know mp4 file structure but do know H.264 packetization. Based on my H.264 Packetization knowledge there seems two two issues.

The Fragmentation Unit structure, itself looks fine.

In your packet file "http://antinori.us/h264.packets.pcap" ,

1. May be PPS (Packet #72) is not correct.The value is the exactly same with SPS(Packet #71). Let's just assume PPS is correct. usually PPS is shorter than SPS ( in my case only 4 bytes - H.264 Baseline profile and even H.264 High Profile.)
2. In the middle of SDP (Packet #67), there is a field "a" with parameter "profile-level-id" the value should be the first 3 byte just after NAL IDR so the value should be "42C01E"

For you information I made a copy of SPS (Sequence Parameter set - Packet #71)

6742c01e924405017fcb080000030008000003018078b177ffffffffffffe0

After 1st NAL unit sequence parameter set byte (67), the next three bytes used for "profile-level-id"